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EngineeringTopic wise MCQs

Environment Engineering MCQ ( Part-6 )

Environment Engineering MCQ


251 Water may not contain much impurity if its source is
(A) Reservoirs
(B) Stream flowing in plains
(C) Lakes in lower regions
(D) Spring along hill slopes
Ans. D

252 If p is total internal pressure, d is diameter of pressure conduit and t is thickness of conduit, the Hoop’s stress is
(A) ????????????/????
(B) ????????????/2????
(C) dp/2t
(D) dt/2p
Ans. C

253 Turbidity of water is expressed
(A) In ppm
(B) In numbers in an arbitrary scale
(C) By pH value
(D) By colour code
Ans. A

254 In plain sedimentation tanks under normal conditions, impurities are removed upto
(A) 60 %
(B) 70 %
(C) 80 %
(D) 90 %
Ans. B

255 In slow sand filters, the turbidity of raw water can be removed only up to
(A) 60 mg/litre
(B) 75 mg/litre
(C) 100 gm/litre
(D) 150 mg/litre
Ans. A

256 Pressure relief valves are provided in water mains
(A) To reduce the pressure
(B) At low points
(C) Upstream of sluice
(D) All the above
Ans. D

257 Biochemical Oxygen Demand (B.O.D.) of safe drinking water must be
(A) Nil
(B) 5
(C) 10
(D) 15
Ans. A

258 At break point of chlorination,
(A) Chlorine is used to oxidise
(B) Residual chloride is zero
(C) Residual chloride is maximum
(D) Residual chlorine reappears
Ans. D

259 The capability of a soil mass of full width and depth to transmit water, is known
(A) Porosity
(B) Permeability
(C) Transmissibility
(D) None of these
Ans. B

260 By boiling water, hardness can be removed if it is due to
(A) Calcium sulphate
(B) Magnesium sulphate
(C) Calcium nitrate
(D) Calcium bicarbonate
Ans. D

261 Percussion drilling is unsuitable in
(A) Unconsolidated sand
(B) Unconsolidated gravel
(C) Quick sand
(D) Consolidated rocks
Ans. D

262 Rapid gravity filters can remove bacterial impurities up to a maximum of
(A) 50 %
(B) 60 %
(C) 70 %
(D) 80 %
Ans. D

263 Continuous flow of water can be expected from
(A) Gravity springs
(B) Surface springs
(C) Artesian springs
(D) None of these
Ans. C

264 Reciprocating pumps
(A) Are not suitable for variable heads
(B) Are four times costlier than centrifugal pumps
(C) Are not suitable for pumping water containing sediments
(D) Single stroke produce pulsating flow
Ans. A

265 Low turbidity of water is detected by
(A) Turbidity tube
(B) Jackson turbidity meter
(C) Baylis turbidimeter
(D) Hellige turbidimeter
Ans. C

266 Silt storage is the same as
(A) Dead storage
(B) Live storage
(C) Effective storage
(D) None of these
Ans. A

267 The type of pipe commonly used in water supply distribution schemes, is
(A) R.C.C. pipes
(B) Hume pipes
(C) Cast iron pipes
(D) G.I. pipes
Ans. C

268 Pick up the incorrect statement from the following. The source of surface water is from
(A) Streams and rivers
(B) Storage reservoirs
(C) Springs
(D) Ponds and lakes
Ans. C

269 The discharge Q = 2????????????????/2.3 log10 (R/rw) for the confined tube well is obtained from
(A) Thiem’s formula
(B) Darcy’s formula
(C) Tolman’s formula
(D) Dupuits formula
Ans. D

270 m and n are monsoon duration factor and catchment factor respectively. If P is yearly rainfall in cm, runoff can be calculated by
(A) Velocity area method
(B) Weir or spillway method
(C) Use of venturi-meter
(D) Using power plant consumption
Ans. A

271 In a rapid gravity filter
(A) Raw water from the source is supplied
(B) Disinfected raw water is supplied
(C) Raw water passed through coagulation tank is supplied
(D) None of these
Ans. C

272 The maximum permissible nitrites in public water supplies, is
(A) Nil
(B) 0.5 P.P.M.
(C) 1.0. P.P.M.
(D) 1.5 P.P.M.
Ans. A

273 Most commonly used section in grade aqueducts, is
(A) Circular
(B) Rectangular
(C) Parabolic
(D) Horse shoe section
Ans. B

274 The most important and widely used tube well in India, is
(A) Strainer well
(B) Cavity well
(C) Slotted well
(D) Perforated pipe well
Ans. A

275 Critical time for developing a water hammer, is the time required for
(A) Closing the valve
(B) The wave to travel from valve to the reservoir
(C) The wave to travel from the valve to the reservoir and back
(D) None of these
Ans. C

276 Bacterias which can survive with or without free oxygen, are known
(A) Aerobic bacterias
(B) Anaerobic bacterias
(C) Facultative bacterias
(D) None of these
Ans. C

277 The standard B.O.D. at 20°C, is taken for the consumption in
(A) 2 days
(B) 3 days
(C) 4 days
(D) 5 days
Ans. D

278 Distribution of wash water is provided in
(A) Sedimentation tank
(B) Slow sand filter
(C) Rapid gravity filter
(D) All the above
Ans. C

279 If P is population of a city in thousands and Q is fire demand in litres per minute, for proper estimate of water, the Empirical formula Q = 1135 [(P/5) + 10] is suggested by
(A) National Board of fire under-writers
(B) Freeman
(C) Kuichling
(D) None of these
Ans. B

280 During treatment of water, sedimentation is done
(A) Before filtration
(B) After filtration
(C) Simultaneously with filtration
(D) Along with chlorination
Ans. A

281 The ratio of the maximum daily consumption to the average daily demand, is
(A) 1.0
(B) 1.2
(C) 1.4
(D) 1.8
Ans. D

282 From the surface of reservoir, evaporation may be minimized by sprinkling
(A) Spirit
(B) Hydrochloric acid
(C) Acetyl alcohol
(D) Methane
Ans. C

283 The transitional middle portion of a logistic curve follows
(A) A geometric growth
(B) A logarithmic growth
(C) A first over curve
(D) A constant rate
Ans. D

284 For plain chlorination of water, the quantity of chlorine used, is
(A) 0.1 mg/litre
(B) 0.2 mg/litre
(C) 0.3 mg/litre
(D) 0.5 mg/litre
Ans. D

285 In distribution pipes, air valves are provided at
(A) Lower points
(B) Junction points
(C) Higher points
(D) Anywhere
Ans. C

286 Manholes along the mains from the source to a city are provided at 500 m intervals in
(A) Steel pipes
(B) R.C.C. pipes
(C) Hume steel pipes
(D) All the above
Ans. D

287 The maximum permissible colour for domestic supplies based on cobalt scale, is
(A) 5 ppm
(B) 10 ppm
(C) 15 ppm
(D) 20 ppm
Ans. D

288 Increase in population of a rapidly growing city, may be estimated by
(A) Arithmetical mean method
(B) Geometrical method
(C) Incremental increase method
(D) Graphical comparison method
Ans. B

289 Per capita demand of water is calculated in litres
(A) Per person per day
(B) Per person per month
(C) Per person per year
(D) None of these
Ans. A

290 Hard water for public water supply is discarded because
(A) ) It consumes more soap
(B) It contains lot of turbidity
(C) It contains pathogenic bacterias
(D) It possesses bad taste and odour
Ans. A

291 Pick up the incorrect statement from the following:
(A) Iron salts produce heavy flocks and hence remove more suspended matter
(B) Iron salts remove hydrogen sulphides
(C) Iron salts can be used over a limited range of pH values
(D) Iron salts impart corrosiveness to water
Ans. C

292 Asbestos pipes are
(A) Light in weight and easy to transport
(B) Highly resistant to corrosion
(C) High flexible to accommodate deflection upto 12°
(D) All the above
Ans. D

293 A strainer type well sunk through three previous layers intervened by three impervious aquicludes, draws water from
(A) Top most pervious layer
(B) Central pervious layer
(C) Lowest pervious layer
(D) All the pervious layers
Ans. D

294 Runoff is the quantity of water which flows
(A) In sewer pipes
(B) Due to leakage in pipes
(C) In rivers
(D) None of these
Ans. C

295 Waste water from bathrooms, kitchens etc. is called _______.
(A) Refuse
(B) Sullage
(C) Sewage
(D) Garbage
Ans. B

296 Pipe which is installed to preserve the water seal in a trap is_____.
(A) Waste pipe
(B) Vent pipe
(C) Anti Siphonage
(D) Soil pipe
Ans. C

297 The trap provided at the junction of house sewer and public sewer line is ______.
(A) Grease trap
(B) Nahni trap
(C) Gully trap
(D) Intercepting trap
Ans. D

298 The depth of water seal in gully trap is about ______.
(A) 50-60 mm
(B) 60-70 mm
(C) 30-40 mm
(D) 20-30 mm
Ans. B

299 A pipe carrying sewage from urinals and W.C. is ______.
(A) Soil pipe
(B) Waste pipe
(C) Vent pipe
(D) Antisyphonage pipe
Ans. A

300 A pipe carrying discharge from kitchens and bathrooms is called_____.
(A) Soil pipe
(B) Waste pipe
(C) Vent pipe
(D) Antisyphonage pipe
Ans. B